A/C belt lower bracket bolt hole partially stripped...

[rundmc]

Hey all,

Was installing a new A/C belt. Went to tighten down the bolts on the tension bracket. I don't go crazy strong-arming ratchets, so I was stunned when, with very little torque and even less warning, the bolt jumped and started the dreaded spin.

Backed it out - not only did the P.O. install the shorter bolt in the lower hole, but it looks like I lost a number of threads - about 3/8 of an inch worth. When we discovered the proper long bolt in the upper hole, we put it in the proper place and it tightened nicely, but I'm worried the missing threads will compromise it and my A/C belt will eventually come flying off.

The problem is the lower bracket hole is somewhat covered up by the rear frame. Is it even possible to tap and helicoil this hole without pulling the engine or the timing cover???

[opethmike]

Right angle drill oughta do it.

[DMCMW Dave]

Just don't drill through and hit the cam gear.

[rundmc]

Just don't drill through and hit the cam gear.

After looking at it, I think I can jack up the engine slightly to clear the frame and get a straight shot at it with a conventional drill. How deep is that hole so I know how far not to go?

[tgraham]

I had this same thread failed on me a really long time ago. I tried offering up a right angle drill and there wasn't enough clearance. You'll have to find a really short profile right angle drill. And then make sure you're getting it absolutely straight!

I sucked it up and pulled the valve cover off (which means pulling the stock exhaust off) and installed a Heli-Coil. If you do the same, it's not the fast route, but at least you know you can get it straight and, as Dave said, not drill through the whole thing :)

Travis

[AdmiralSenn]

+1 on the Heli-Coil route, only I did it after I took the rear fascia off, then undid the motor mounts and jacked the engine up slightly (it seemed like less work to me than dismantling the engine proper).

Working fine a year later, no leaks, bracket is sturdy and I managed not to drill into anything I shouldn't. I used tape on the drill bit to make sure it didn't go any deeper than the original hole.

[rundmc]

I used tape on the drill bit to make sure it didn't go any deeper than the original hole.

That's a great idea!

[Spittybug]

That's a great idea!

Safer than tape is to either grind the bit down to a short length so it can't possibly go too far or use a drill stop. It can be difficult to stop the "pull" of the bit as it is breaking through the opposite side, especially if you can't adequately brace yourself when drilling.

[John U]

The bolt that holds the pulley bracket on was originally a M7x30mm. Mine was also stripped out, so I used an M7x40mm...it holds fine and no helicoil required.

John

[rundmc]

The bolt that holds the pulley bracket on was originally a M7x30mm. Mine was also stripped out, so I used an M7x40mm...it holds fine and no helicoil required.

John

Thanks! I will try this as well!